Boilers

Boilers

Boilers are used for vaporization of liquids by passing the steam in the coils. Boilers are made by fusing number of parallel coils in a glass shell. In Boilers, coils are designed to provide bigger cross section in the shell side as compared to condensers. o The average heat transfer in Boilers is considered as 350 Kcal/m2,hr, C at a steam pressure of 3.5 bar.

Note on use of Boilers :

• Vapours should be passed through shell only.
• Steam should be passed in the coils at a maximum pressure of 3.5 bar which is equalant to a temperature of 147 °C.
• For higher temperature (maximum upto 200 °C) heat transfer fluids can be passed in the coils. – Cold liquids
• Cold liquids should be preheated for better results.
• Boilers should bemounted in an external circulatory loop (as shown in figure) and not direct at the bottom of flask or column
• Under certain circumstances, boilers can be mounted in series to provide larger heat transfer area.